1. Field
Embodiments of the following description relate to a spatial parameter encoding apparatus and method, and a spatial parameter decoding apparatus and method. More particularly, embodiments of the following description relate to an apparatus and method for encoding and decoding a spatial parameter using a correlation between spatial parameters.
2. Description of the Related Art
Generally, a scheme of encoding a multi-channel audio signal includes waveform multi-channel audio coding, and parametric multi-channel audio coding. Here, the multi-channel audio signal refers to a signal with at least two channels.
The waveform multi-channel audio coding typically includes, for example, Moving Picture Experts Group (MPEG)-2 multi-channel audio coding, Advanced Audio Coding (AAC) multi-channel audio coding, and BSAC (Bit-sliced arithmetic coding)/AVS (Audio Video Standard) multi-channel audio coding. Additionally, the parametric multi-channel audio coding typically includes MPEG surround coding.
In particular, in the MPEG surround coding, a multi-channel audio signal may be restored using a signal obtained by down-mixing the multi-channel audio signal, and using a spatial parameter indicating a characteristic relationship between channels. Phase difference information among spatial parameters may be used to improve spatiality of an audio signal, however, may not be used to reduce a bit amount at a low bit rate. A bit amount of a spatial parameter may also be reduced by adjusting a quantization level, however, a sound quality may be degraded.
Accordingly, there is a desire for a method of improving a spatiality based on a low bit rate, even when a small amount of spatial parameters is used.